Shape armholes

I am confused, new at this! Pattern says
Shape armhole
Cast off 2 sts purl to end
work 6 rows dec 1 st at armhole edge in next and foll alt row

Is the armhole edge at the beginning of the next row or the end where I cast off 2 sts?

Welcome to KH!
The armhole edge is where you cast off the 2sts. You’re going to continue shaping that armhole by decreasing at that edge.
Is this a cardigan front? Can you give us a link to the pattern or a pattern name?

Thanks, so decrease at end! It is the right front of a bolero!
James C Brett JB016 is the pattern

OK, yes, that makes sense. Bind off on the wrong side row, a purl row.
Good luck with this very nice pattern.